The invention relates to forming a wound glass filament web from a formaldehyde-free binder composition that includes carboxy functional polymer.
Wound glass filament webs formed from continuous or substantially continuous filaments are used in a variety of applications including insulation (e.g., thermal and acoustic), filters (e.g., air filters, furnace filters, air conditioner filters and oven range filters), sky light diffusion, and glass filament reinforced plastics. For many applications, it is important that the web exhibit uniform functional properties across its major surfaces. If the web includes rips, tears or openings created by tearing and ripping, the functional properties of the web may not be uniform or may be impaired. For most applications, it is necessary to have a web that is free from tears and rips in order for the web to exhibit performance properties suitable for the intended application and to minimize waste due to poor quality.
Many wound glass filament web manufacturing processes involve exerting stretching and pulling forces on the web while the web is in a wet state so as to achieve an expanded web. The stretching operation can cause the web to rip or tear and render the web unsuitable for its intended purpose.
Wound glass filament webs formed from continuous or substantially continuous filaments have been made using a variety of binder compositions including polyvinyl alcohol, polyester, latex polymer, and formaldehyde (e.g., urea, melamine, and phenol formaldehyde)-based binder compositions. In the case of formaldehyde-based binder compositions, when the glass filament web is heated to cure the binder composition, formaldehyde derived compounds are volatilized from the composition and into the surrounding environment, which is undesirable for the people working around the web manufacturing process and may be harmful to the environment.
Wound glass filament webs differ from what is commonly referred to as fiberglass insulation in that fiberglass insulation is often made by pneumatically conveying discontinuous glass fibers formed from molten attenuated glass.